Well to solve this firstly we should calculate her average speed while she was going to work. Which comes out to be 45 miles per hour.
Now if her average speed while going home is half as fast as while coming to work was, the answer would be 22.5 miles per hour. So the average speed for the total journey would be the average for these two values. As the distance was same for both the journeys we can simply do 45 + 22.5 / 2 = 33.75 mph.
x should equal -2 and y should equal -3 to solve this i multiplied the first equation by 2 then got rid of the 4y and -4y then i added the 14x to the 9 equaling 23x and added the -40 to the -6 which became 23x=-46 i solved this getting -s for x, then i plugged that into the equations to get y which was -3